1. Field of the Invention
The present invention generally relates to hair dyes and, more particularly, to a new hair dye using a fresh natural indigo leaf or a juice of a fresh natural indigo leaf. The present invention also relates to a method for dyeing hair using such dyes.
2. Description of the Prior Art
Conventionally, several compositions and methods for dyeing hair have been known. Examples of such a known hair dyeing dye include a synthesized hair dye using an oxidation dye which have a high hair-dyeing performance as well as a long-lasting performance, a plant-based hair dye which contains “henna” as its primary component and is widely used in Europe and in the US, and a hair dye commonly referred to as “hair manicure”, to which an acid dye is blended.
Each of the known hair dyes is associated with certain drawbacks. Oxidation dyes are known to cause allergies in humans. The “henna” dye has a limited variation in color and does not go well with the black hair of the Japanese. Some allergic events are also reported for the dye. Acid dyes have a low durability since the dyes are just soaked up by the hair. Some of the conventional hair-dyeing agents are known to stain skin when spilt onto skin.
A hair dye is proposed in Japanese Patent Laid-open Publication No. Hei 10-53720 which is made by emulsifying or suspending a powdered plant-based dye together with liquid silicone, paraffins, a plant or animal oil using a surfactant or the like. Though this hair dye has an improved agent stability as well as an enhanced functionality in terms of hair-dyeing operation, it has a relatively low hair-dyeing performance, a property which should be prioritized for a hair dye. Thus, this hair dye does not meet all of the requirements either.
The indigo plant has long been grown by mankind and has a long history of being used as a dye for dyeing fibers, a coloring agent for food, or a medicament such as a detoxifying agent or an antipyretic agent. Making use of the dye component of the indigo in dyeing hair may provide those who are sensitive to conventional hair dyes with the benefit of dyeing their hair without having troubles. Furthermore, the indigo dyes are free of irritation and damage to scalps and hair and give hair body and a new texture of hair, providing a hair-dyeing effect that suits hair color of the Japanese.